1. Field of the Invention
The present invention relates a disk brake for motorcycles and, more particularly, to such a disk brake, which has means to dissipate heat and to guide out dust during braking action.
2. Description of the Related Art
FIG. 1 illustrates a disk brake for use in a motor vehicle according to the prior art. This structure of disk brake comprises a center coupling portion 1xe2x80x2, an annular friction face 3xe2x80x2 concentrically disposed around the center coupling portion 1xe2x80x2, and a plurality of supporting ribs 2xe2x80x2 radially connected between the center coupling portion 1xe2x80x2 and the annular friction face 3xe2x80x2. This structure of disk brake is still not satisfactory in function. Because the supporting ribs 2xe2x80x2 are straightly connected between the center coupling portion 1xe2x80x2 and the annular friction face 3xe2x80x2 and each supporting rib 2xe2x80x2 has two opposite lateral sidewalls made in vertical, the disk brake does not cause currents of air through the holes in it when rotated. Therefore, this structure of disk brake cannot quickly dissipate heat upon each braking action. Further, because the annular friction face 3xe2x80x2 is a solid face, dust tends to be accumulated in between the annular friction face 3xe2x80x2 and the wheel of the motor vehicle, resulting in poor braking performance and short service life of the disk brake.
The present invention has been accomplished to provide a disk brake, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a disk brake, which dissipates heat quickly upon each braking action. It is another object of the present invention to provide a disk brake, which prevents accumulation of dust in between the friction face and the wheel of the motor vehicle. It is still another object of the present invention to provide a disk brake, which is durable in use. To achieve these and other objects of the present invention, the disk brake having supporting ribs radially spirally connected between the center coupling portion and annular friction face thereof and equiangularly spaced from one another. Each supporting rib has two opposite lateral sidewalls axially sloping in one direction and respectively curved inwards for causing currents of air for dissipating heat upon each braking action of the disk brake. According to another aspect of the present invention, the friction face of the disk brake has radially spirally extended rows of guide holes for guiding out dust upon friction between the disk brake and the wheel of the motor vehicle.